1. Field of the Invention
The present invention relates to graphics systems, and more specifically to a method and apparatus for upscaling a source image to generate a destination image.
2. Related Art
Graphics systems often display images on display screens. For example, a computer system may display the image of an object on a flat-panel monitor. Television systems and cameras are some of the other examples of such graphics systems. To achieve the display of an image, the image is generally represented by image data (e.g., RGB data or YUV data), and display signals are generated from the image data. The display signals cause the image to be displayed on a corresponding display screen.
During such a display, a graphics system may need to upscale the image. The upscaling may be needed for one or more of several reasons. For example, a source image may be provided in one resolution (e.g., 160.times.120 size image data from a CD-ROM decoder), and the image may need to be displayed on a larger display screen (e.g., 640.times.480 CRT screen). To take advantage of the larger display area, a graphics system may upscale the image.
In addition, with the advancements in user interfaces, a user of a graphics system may wish to have the image resized without maintaining the aspect ratio of the source image. That is, the image may need to be upscaled by different factors with regards to the length and the width. Thus, a user may specify that the image be doubled in the length dimension while upscaling the breadth dimension by a factor of 1.5. A well-designed graphics system should be able to meet such different needs of a user.
Graphics systems typically include special circuitry to upscale images. Examples of such circuitry include well-known graphics controller chips typically housed on a mother board of a computer system and special chip sets provided with LCD panels of computer systems and video cameras.
While providing the upscaling functionality, the special circuitry may need to meet specific requirements of the environment of usage. For example, if the special circuitry is used in a flat monitor, the circuitry may need to be compact. Without such compactness, the circuitry may be unsuitable for flat monitor environments where it is critical that circuitry occupy minimal space. In addition, it may be desirable to keep to a minimal level the total amount of power consumed by the special circuitry, particularly in the portable applications market (e.g., laptop computers).